This module can connect 3 video sources and you can switch between different video sources with a 3 position switch to your ground station. If you have multiple cameras on your plane, this is what you need. 3 channel switch over module, adopts high speed video switch chip, effectively reduce the vibration of the Video image. The control channel can be any proportional channel or 3-position switch channel. (2-position switch channel can only switch within two video input signals), "-" is negative pole," " suspend,"S" is receiving Video signal.